The Beta-Decay of the Triton

A general formula is derived for the beta-decay matrix elements in the decay of a nucleus into its mirror nucleus. This formula is specialized to the decay of ${\mathrm{H}}^3$. Under the assumption of charge independence of nuclear forces, it is shown that the value ${\left(\int \sigma \right)}^2=3\mathrm{}$ computed on the basis of a pure ${}_{}{}^2{}_{}{}^{}S_{\frac{1}{2}}^{}{}_{}{}^{}$ ground state is an upper limit for the true value of this matrix element, provided only that the ${}_{}{}^2{}_{}{}^{}S_{\frac{1}{2}}^{}{}_{}{}^{}$ state is present with a probability of at least 25 percent.